We propose to establish an interdisciplinary postdoctoral training program for all aspects of research into the biology of stem cells. A major strength of this program is the range of expertise at University of Wisconsin in stem cell biology - from basic embryology, through clinical trials, to ethics and policy research. Postdoctoral trainees from specific areas of developmental biology, neuroscience, endocrinology, blood science, heart science, bioengineering, and other specialties such as policy and ethics will enter this program and be matched with the primary mentor appropriate for their area of interest. In addition, there will be opportunities to study the ethical implications of stem cell research. Key aspects of the program include (i) establishing mentor committees with direct interest in stem cell biology, (ii) encouraging active interactions with other laboratories involved with stem cell research through seminars, journal clubs, workshops, and retreats, (iii) attending UW-Madison courses related to stem cell biology and research ethics, and (iv) interacting with the key institutes on campus which have become central to stem cell biology, including the Biotech Center, Waisman Center, Primate Center, and the non profit organization WiCell. The trainees will participate in a number of newly developed courses in stem cell biology - from basic principles to applications. They will be made aware of the huge commercial implications of stem cell biology and the latest thinking on translating this potential into clinical trials. The investigators aim to train a future generation of principal investigators within this important new field. All laboratories in this program which work with human embryonic stem cells will continue to use only Federally-approved cell lines, specifically WA01, WA07, WA09, WA13, and/or WA14.